1. Technical Field
The present invention relates to a liquid ejecting apparatus which ejects liquid by applying a drive signal to an actuator, a control method thereof, and a program, and is preferable for a liquid ejection type printing apparatus which is designed to print predetermined characters, images, and the like by ejecting minute liquid droplets from nozzles of a liquid ejecting head and forming fine particles (dots) on a print medium.
2. Related Art
As one example of liquid discharging apparatuses, an ink jet printer which discharges ink (liquid) from nozzles provided at a head to a recording medium has been known. Generally, a serial head scheme in which a nozzle array including multiple nozzles aligned in a predetermined direction is formed at a head and an image with a nozzle array width is printed by the head discharging ink while relatively moving in an intersecting direction between a scanning direction of the head and a transport direction of a recording medium, for example, a line head scheme in which nozzles are arranged in an array in a direction intersecting with a transport direction of a print medium and an image is printed when the print medium passes below the nozzles, and the like as disclosed in JP-A-2011-5733, and the like have been known.
Methods of ejecting liquid from nozzles of a liquid ejecting head include an electrostatic scheme, a piezoelectric scheme, and a film boiling liquid ejecting scheme. In a case of the piezoelectric scheme, for example, if a drive signal is applied to a piezoelectric element as an actuator, then a vibration plate in a cavity is displaced, pressure change occurs in the cavity, and liquid is ejected from nozzles by the pressure change. In a case of a serial head scheme high-speed printer in which liquid is ejected at a high speed by causing a liquid ejecting head to perform scanning at a high speed and driving a large number of piezoelectric elements in short time, and in a case of a line head scheme liquid ejection type printing apparatus or the like in which liquid is ejected at the same time from a plurality of nozzles by simultaneously driving a plurality of piezoelectric elements, it is necessary to drive a large number of piezoelectric elements, and burden applied on a drive circuit per unit time is significantly large. Therefore, it is generally difficult to generate the drive signal by using the same configuration as that of a serial head scheme ink jet printer in the related art, which has been provided in the consumer market, without any change.
Thus, a method of using a plurality of Digital-to-Analog Converters (DACs) and a plurality of amplifying circuits (hereinafter, also referred to as amplifiers) to generate a plurality of drive signals and equally dividing the number of nozzles to be supported by one drive signal can be considered. However, in a case of providing the plurality of DACs and amplifiers, errors of the respective DACs and errors of the respective amplifiers increase in a multiplied manner due to the combination thereof. If errors of the driven piezoelectric elements are further taken into consideration, errors as a whole further increase. As a result, it is difficult to perform overall control, and quality of a material produced by the liquid ejection type printing apparatus may deteriorate.
Here, it is preferable to generate the drive signal by using a single DAC and a single amplifier in order to minimize an influence of the errors. However, there is a limitation in power supply of the amplifier (for example, there is a limitation in allowable current of a circuit in an output stage). Therefore, it is not possible to appropriately drive a large number of piezoelectric elements and quality of the produced material deteriorates in the case of the piezoelectric scheme, for example, and therefore, such a configuration is not realistic.